1. Field
The present disclosure relates to a deposition mask assembly and a method of manufacturing a display device using the same.
2. Description of the Related Art
Among light-emitting display devices, an organic light-emitting display device, which is a self-luminescent display device, has advantages of a wide viewing angle, high contrast, and rapid response speed. Therefore, the organic light-emitting display device has attracted considerable attention as a next-generation display device.
The organic light-emitting display device is provided with a light-emitting layer made of an organic luminescent material between an anode electrode and a cathode electrode. When positive and negative voltages are respectively applied to these electrodes, holes discharged from the anode electrode are transferred to the light-emitting layer through a hole injection layer and a hole transport layer, electrons discharged from the cathode electrode are transferred to the light-emitting layer through an electron injection layer and an electron transport layer, and the electrons and holes are recombined in the light-emitting layer, so as to generate excitons. When these excitons are changed from an excited state to a ground state, light is emitted from the light-emitting layer, thereby displaying an image.
The organic light-emitting display device includes a pixel defining film having an opening portion for exposing an anode electrode formed for each pixel. A hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, and a cathode electrode are sequentially formed on the anode electrode exposed through the opening portion of the pixel defining film. Among these, the hole injection layer, the hole transport layer, the light-emitting layer, the electron transport layer, and the electron injection layer may be formed by various methods. One of the various methods is a deposition method. For example, in the deposition method, a small mask scanning (SMS) deposition method may be used, i.e., a substrate or a deposition source may be moved, while the substrate is spaced apart from a mask having a smaller size than the substrate.